The present invention relates to thin-film magnetic heads used in magnetic disk drives or the like, and more particularly, to size reduction of a thin-film magnetic head.
In magnetic disk drives such as hard-disk drives, the head slider equipped at a leading end of a magnetic head assembly is caused to fly above a magnetic disk to write information thereonto or read written information therefrom using a thin-film magnetic head formed at an edge of the head slider.
Some such types of thin-film magnetic heads each have: a coil for writing information onto the magnetic disk by converting, into a magnetic field, electrical signals associated with the information to be written; and a giant magnetoresistive (GMR) element for reading written information from the magnetic disk by reconverting into the original electrical signals the magnetic field generated according to the written information.
Such a thin-film magnetic head is manufactured using a thin-film forming process that includes such steps as shown in FIG. 4, for example. That is to say, a lower shield layer 210 is formed at an edge 200 of a head slider first (step A in FIG. 4). Next, after the formation of an insulating layer on the lower shield layer 210, a GMR element 211 and two lead electrode pieces, 220a, 220b, both for electrical connection to the GMR element 211, are further formed above the insulating layer (step B in FIG. 4).
Also, a first low-resistance lead layer 221a and a second low-resistance lead layer 221b are formed on the two lead electrode pieces, 220a, 220b, respectively (step C in FIG. 4) and then an insulating film is further formed on both of the two low-resistance lead layers, 221a, 221b. 
At this time, electrical conducting holes 222a, 222b that penetrate the insulating films are formed in part of the two low-resistance lead layers 221a, 221b, respectively, by using a lift-off process (step D in FIG. 4). In addition, connection object selector pads 223a, 223b are formed over the two electrical conducting holes, 222a, 222b, respectively (step E in FIG. 4).
Furthermore, a first conductor 260a and second conductor 260b for establishing electrical continuity with respect to the low-resistance lead layers 221a, 221b, respectively, are formed above the connection object selector pads 223a, 223b, respectively (step G in FIG. 4). The first conductor 260a and the second conductor 260b are further insulated with alumina, an upper face of which is then exposed by chemical-mechanical polishing (CMP).
Next, first read wiring 270a with one end connected to the first conductor 260a and the other end extending to a forming position for a first read terminal 231a (see step J in FIG. 4), and second read wiring 270b with one end connected to the second conductor 260b and the other end extending to a forming position for a second read terminal 231b (also, see step J in FIG. 4), are formed in step H of FIG. 4. Thus, the first read terminal 231a and the first low-resistance lead layer 221a are selectively connected to each other and at the same time, the second read terminal 231b and the second low-resistance lead layer 221b are selectively connected to each other.
Meanwhile, an upper shield layer 212 is formed over the GMR element 211 (step E in FIG. 4) and a lower magnetic pole layer 213 is formed on the upper shield layer 212 (step F in FIG. 4).
Next, a first layer coil 214 is formed on the lower magnetic pole layer 213, and first write wiring 250a that extends from the first layer coil 214 to a forming position for a first write terminal 241a (see step J in FIG. 4) is formed (step G in FIG. 4). Additionally, a second layer coil 215 is formed and second write wiring 250b that extends from the second layer coil 215 to a forming position for a second write terminal 241b (see step J in FIG. 4) is formed (step H in FIG. 4).
Furthermore, an upper magnetic pole layer 216 covering the second coil layer 215 is formed (step I in FIG. 4), and the first read terminal 231a and second read terminal 231b respectively covering one end of each of the read wiring 270a and the read wiring 270b, and the first write terminal 241a and second write terminal 241b respectively covering one end of each of the write wiring 250a and the write wiring 250b, are formed via copper studs 230a, 230b, 240a, 240b (step J in FIG. 4). A thin-film magnetic head is thus manufactured.
In the thin-film magnetic head manufactured using such a process, the forming positions for the two conductors 260a, 260b that are to be formed above the two connection object selector pads 223a, 223b, the layout of the two sets of read wiring 270a, 270b and other factors are properly set to selectively connect each of the two read terminals 231a, 231b to either of the two low-resistance lead layers 221a, 221b (see Patent Reference 1 (Japanese Patent Laid-open No. 2002-367133), for example).